In landline and wireless networks, a feature known as Caller-ID allows users to view the telephone number of the person who is calling them. The telephone number of the calling party typically is displayed on a display device of the user's telephone. A signaling protocol known as Signaling System 7 (SS7) provides for transmitting signaling information that includes the telephone number of both the calling and called parties. The signaling information is transmitted over a different channel from the channel over which the voice or data is transmitted. Components in the network route the signaling information and the voice and/or data to the called party's telephone. Logic in the telephone causes the telephone number of the calling party to be displayed on the display device of the called party's telephone.
A party who is placing a call has the ability to block the telephone number of the telephone from which the call is being placed by entering a specific series of digits immediately preceding the telephone number of the party they are calling. For example, in some landline networks, if the digits “*67” are dialed immediately prior to dialing the telephone number of the party who is being called, the telephone number of the party who is placing the call will be blocked, and therefore will not be displayed on the called party's telephone. This is useful in various situations in which the calling party desires to preserve his or her privacy by preventing his or her telephone number from being revealed.
SMS is a messaging protocol that allows short text messages to be sent via wireless networks to and from wireless devices, such as, for example, wireless telephones, personal digital assistants (PDAs), etc. The wireless network has components that are responsible for determining the destination addresses and for transporting the short messages between the SMS centres (SMSCs) and the wireless devices. In contrast to other existing text-message transmission services, such as alphanumeric paging, SMS provides guaranteed delivery of text messages because the message is stored in the SMSC until the destination wireless device becomes available. Thus, SMS provides a store-and-forward service for short (i.e., no more than 160 alphanumeric characters) text messages.
As wireless networks and technology have evolved, a variety of services that use SMS have been introduced, including, for example, email, fax, paging, interactive banking, information services and integration with Internet-based applications. Although SMS messaging continues to grow, it is not currently possible for a sending party who is sending an SMS message to block the sending party's identification (ID) information (e.g., email address or telephone number). It would be desirable to provide a feature that enables a sender of an SMS message to block the sender's ID information, thereby preventing the sender's ID information from being displayed on the intended recipient's wireless device.